Radioactive Pollution: A Never Ending Hazard

Today in the 21^st century, mankind has achieved great feats in every walk of life. New technologies are being developed and upgraded for efficient working of human civilization. Newer energy sources are looked for and their optimal capabilities are harnessed by us. One such avenue is RADIOACTIVE ENERGY which has numerous applications in every sector.

Radioactive isotopes (radionuclides) are present naturally everywhere, which includes our bodies, food and water. Half-life of radio-isotopes range from hundreds to thousands of year i.e huge amount of time required to reduce their radioactivity by half. All living beings encounter radiation on a daily basis. It comes from space, naturally-occurring radioactive materials (radionuclides) found in the soil, water and air.

Radiation is basically of two types:

1. Non-ionizing radiations: These are electromagnetic waves of longer wavelength from near ultraviolet rays to radiowaves. They possess energies enough to excite the atoms and molecules of the medium through which they are moving, causing them to vibrate faster. These do not have enough energy to ionize them.

2. Ionizing radiations: These are electromagnetic radiations having high energy, such as short wavelength ultra violet radiations, x-rays and gamma rays. The energetic rays like (,  and  etc.) produced in radiocative decay can cause ionization of atoms and molecules of the medium through which they pass and convert them into charged ions.

   Alpha (), beta () and gamma () radiations are produced by the process called radioactive decay. Their unstable nuclei decay spontaneously and emit radiations. It can affect other non-radioactive atoms to become radioactive and give out radioactive radiations. If the level of these radioactive radiations increases beyond a certain limit it causes harmful effects to living beings. This harmful level of radiations emitted by radioactive elements is called radioactive pollution.

   GENERATION OF RADIOACTIVE WASTE:

   Radioactive waste is generated due to following actions:

   1. Energy production– Radioactive material that are produced in nuclear reactors by fission process itself or by the neutrons emitted is called reactor-produced or by-product material. Radiations may leak from nuclear reactors and other nuclear facilities even when they are operating normally. It is often feared that even with the best design, proper handling and techniques, some radioactivity is routinely released into the air and water.

   2. Biological research-Many of the radio-isotopes are commonly used in biological research, such as ³H, ¹⁴C, ³⁵S, ³²P, ¹²⁵I, ³³P and ¹³¹I, are by-product materials.

   3. Natural occurence-A naturally-occurring radioactive material is any radioactive material that occurs naturally on earth. All naturally-occurring radioactive material is regulated by each state. Radium-226 is widely distributed in rocks, sediments and soils along with isotopes of uranium.

   4. Diagnostics : X-rays are used for general radiology and CT scan. Gamma rays are used for treating cancer. The by-product of these procedures are radioactive.

   5. Nuclear Tests : Nuclear explosion tests performed out in the atmosphere are a major cause of radioactive pollution and is responsible for increasing the background level of radiation throughout the world.

   HAZARDS OF RADIOACTIVE WASTE:

   1. Living beings exposed to high doses of radiation display various types of detrimental effects. Examples of such effects in humans are erythema (reddening of the skin), epilation (loss of hair), cataracts and “acute radiation syndrome.”

   2. The induction of changes in hereditary traits caused by radiation damage to the chromosomes is known as radiation mutagenesis.

   3. In genetic damage, genes and chromosomes get altered & may become visible as deformations in the offsprings (children or grandchildren). In nongenetic effects, the harm is visible immediately in the form of birth defects, burns, some type of leukemia, miscarriages, tumors, cancer of one or more organs and fertility problems.

   4. The flora and fauna are also damaged with altered patterns of growth observed in various plants and animal species.

   As we all know that the degradation of such radioactive waste is difficult, but there are some biological solutions that would mitigate this problem.Many microbes like bacteria and fungus could help in degradation of such radioactive pollutants thereby helping other organisms to sustain their biological functions.

   The red-coloured bacterium Deinococcus radiodurans can resist 1.5 million rads of gamma radiation, about 3,000 times the amount that would kill a human. The bacterium survives and reproduces in environments that would be lethal for any other organism and it also resists high doses of ultraviolet radiation. The most important component of this radiation resistance is the ability of the bacteria to repair damage to its chromosomal DNA. Researchers hope that they can manipulate it in such a way that it will be able to detoxify the thousands of toxic waste sites which contain radioactive material.

   

   This article is the first part of a two-part series on the topic  “MICROBIAL SOLUTIONS IN BIOREMEDIATION OF RADIOACTIVE WASTE“

   REFERENCES:

   1. http://www.guinnessworldrecords.com/world-records/most-radiation-resistant-lifeform

   2. https://www.jstor.org/stable/2438741

   3. Understanding the effects of radiation on health Editors Dr. Ch. Desaintes, Dr. G. Neale Kelly, Ms Karin Coiffard

   4. http://www.bic.mni.mcgill.ca/~llchia/HP_lectures/biological_effects.pdf

   5. http://documents.manchester.ac.uk/display.aspx?DocID=26898

   6. http://webfiles.ehs.ufl.edu/rssc_biological_effects_ionizing_rad.pdf

   7. https://www.ehs.washington.edu/rsotrain/radprotectionprinciples/biological_effects.pdf

   8. http://www.scielosp.org/pdf/rpsp/v20n2-3/12.pdf

Also Read – Mitigating Antibiotic Resistance With Efficient Wastewater Treatment